JP4239499B2 - ORGANIC ELECTROLUMINESCENT ELEMENT, IMAGE FORMING APPARATUS USING SAME, PORTABLE TERMINAL, ORGANIC ELECTROLUMINESCENT ELEMENT MANUFACTURING METHOD - Google Patents

Description

【０２７９】
ここで、（表１）の評価項目における評価方法及びその評価基準について説明する。
【０２８０】
素子の発光効率は、有機エレクトロルミネッセンス素子に一定電流を流したときの発光輝度を評価した。その評価基準は、比較例１の発光輝度に対して、◎：非常に優れている、○：優れている、△：許容できる、である。
【０２８１】
発光面の視認性は、有機エレクトロルミネッセンス素子を３００μｍの画素からなる画像形成装置としたときの、光のにじみ、ぼけについて、視認性の程度を目視にて評価した。評価は、◎、○、△の三段階評価であり、その評価基準は、◎：非常に優れている、○：優れている、△：許容できる、である。
【０２８２】
発光面の視認性保護は、有機エレクトロルミネッセンス素子の表面についたごみの取り除きやすさについて評価した。その評価基準は、比較例１の取り除きやすさに対して、◎：非常に優れている、○：優れている、△：許容できる、である。
【０２８３】
（表１）から明らかなように実施例１、２、３、４の各有機エレクトロルミネッセンス素子は、比較例１の有機エレクトロルミネッセンス素子に対して、発光輝度、発光面視認性において、すべて優れた結果となった。特に、実施例１及び４においては、発光輝度、発光面視認性が比較例１と比べて非常に優れた結果となった。ただし、発光面視認性保護については、実施例１、２、４の各有機エレクトロルミネッセンス素子では、比較例１の有機エレクトロルミネッセンス素子よりも劣る結果となったが、これは平坦化面がないことによる効果であり、実用上特に問題はない。本実施例の有機エレクトロルミネッセンス素子は比較例１に対し顕著に発光効率が高く、視認性に優れた有機エレクトロルミネッセンス素子であることがわかる。
【０２８４】
【発明の効果】
以上のように、本発明の有機エレクトロルミネッセンス素子によれば、以下のような有利な効果が得られる。
【０２８５】
請求項１に記載の発明によれば、
（１）基板と対向する光取り出し面上に、少なくとも２つ以上の大きさの異なる略半球状の微小レンズ群が形成されているので、光取り出し面／空気界面の面積が増大し、界面における全反射の確率が低下し、光の取り出し効率が向上する。
【０２８６】
（２）基板と対向する光取り出し面上に、少なくとも２つ以上の大きさの異なる略半球状の微小レンズ群が形成されているので、光取り出し面／空気界面における全反射が抑制され、光の取り出し効率が向上する。
【０２８７】
（３）基板と対向する光取り出し面上に、少なくとも２つ以上の大きさの異なる略半球状の微小レンズ群が形成されているので、レンズ効果により光の配光が変化するため、実効的な輝度が向上する。
【０２８８】
（４）光取り出し面上に直接微小レンズ群が形成されているので、レンズ構造と発光部との距離を小さくすることができる。
【０２８９】
（５）光取り出し面上に直接微小レンズ群が形成されているので、基板による光のロスが発生せず、光の取り出し効率が向上する。
【０２９０】
（６）光取り出し面上に直接微小レンズ群が形成されているので、画素面の横方向への光の伝達が抑制されるため、光にじみ等の視認性の低下を伴うことなく光の取り出し効率が向上する。
【０２９１】
（７）光取り出し面上に、少なくとも２つ以上の大きさの異なる微小レンズ群が直接形成されているので、画素形状や面積に対する制約がなく、長期に渡って効率の良い発光を維持することができる。
【０２９２】
（８）光取り出し面上に、少なくとも２つ以上の大きさの異なる微小レンズ群が直接形成されているので、作製プロセスが簡単であり、容易に作製することができる。
【０２９３】
請求項２に記載の発明によれば、
（１）基板と対向する光取り出し面上に、微小レンズ群と平坦化面とが形成されているので、微小レンズ群／空気界面の面積が増大し、界面における全反射の確率が低下し、光の取り出し効率が向上する。
【０２９４】
（２）基板と対向する光取り出し面上に、微小レンズ群と平坦化面とが形成されているので、微小レンズ群／空気界面における全反射が抑制され、光の取り出し効率が向上する。
【０２９５】
（３）光取り出し面上に直接微小レンズ群が形成されているので、レンズ構造と発光部との距離を小さくすることができる。
【０２９６】
（４）微小レンズ群の光取り出し面側に、空気層および一部の接点を介して、その表面が平坦となる平坦化面とを形成されているので、光取り出し面の表面にゴミ等が付着しても、光の取り出し効率の値が低下しない。
【０２９７】
（５）光取り出し面側に平坦化面を形成されているので、光取り出し面の表面にゴミ等が付着しても、容易に取り除くことができる。
【０２９８】
（６）光取り出し面側に平坦化面を形成されているので、微小レンズ群が直接外気と接触していないため、長期に渡りレンズの効果を保持することができる。
【０２９９】
（７）光取り出し面側に平坦化面を形成されているので、光取り出し面の表面に外光による視認性低下を防ぐためのシート等を容易に形成することができる。
【０３００】
（８）光取り出し面側に平坦化面を形成されているので、外部から力が加わっても、微小レンズ群の形状が変化するのを抑制することができる。
【０３０１】
（９）光取り出し面側に平坦化面を形成する微小レンズ群からなるため、平坦化面を厚くしても光の取り出し効率への影響が小さいため、微小レンズ群の強度を保つことが容易である。
【０３０２】
請求項３に記載の発明によれば、請求項１又は２の効果に加え、
（１）光取り出し面上に光学結合材を介して微小レンズ群を貼り付けているので、発光部と微小レンズ群を個別に作製することができ、微小レンズ群を形成する際に発生する発光層へダメージを与える要因の影響をなくすことができ、微小レンズ群および発光部を容易に作製することができる。
【０３０３】
（２）光取り出し面上に光学結合材を介して微小レンズ群を貼り付けているので、発光部と微小レンズ群を個別に作製することができ、微小レンズ群をひとつのシートとして形成することが可能であり、取り扱いが容易である。
【０３０４】
（３）発光部と微小レンズ群とを個別に作製することができるため、光取り出し面側に平坦化面を形成してなる微小レンズ群をひとつのシートとして形成することが可能であり、シートの両表面が平坦であるため取り扱いが容易である。
【０３０５】
（４）光取り出し面上に光学結合材を介して微小レンズ群を貼り付けているので、微小レンズ群および発光部の表面形状が一致していなくても、容易に貼り付けることができる。
【０３０６】
（５）微小レンズ群と平坦化面からなる微小レンズ群をひとつのシートとして形成することができるため、外光による視認性低下を防ぐためのシートと一体化したシートとすることができ、容易に形成することができる。
【０３０７】
請求項４に記載の発明によれば、請求項１乃至３の内いずれか１の効果に加え、
（１）微小レンズ群の屈折率が大きいため、全反射により微小レンズ群に到達できない光を減少させることができ、光の取り出し効率が向上する。
【０３０８】
（２）微小レンズ群の屈折率が大きいため、微小レンズ群に到達する光が増加し、微小レンズ群のレンズ効果を有効にすることができ、光の取り出し効率が向上する。
【０３０９】
（３）微小レンズ群の屈折率が大きいため、発光層から放射される光が発光面の法線方向に立った配向となり、素子内部での光損失を減少させることができ、視認性に優れた、高効率の発光性能を維持することができる。
【０３１０】
請求項５に記載の発明によれば、請求項１乃至４の内いずれか１の効果に加え、
（１）素子内部での光損失を減少させることができるため、視認性に優れた、高効率の発光性能を維持することができる。
【０３１１】
（２）素子内部での光損失が減少し、全反射により空気中へ取り出されない光が反射電極に反射され再利用することができるため、視認性に優れた、高効率の発光性能を維持することができる。
【０３１２】
請求項６に記載の発明によれば、請求項１乃至５の内いずれか１の効果に加え、
（１）加工のしやすい部材と強度の保持できる部材のように、機能を分担することが可能であるため、材料の選択肢が増加する。
【０３１３】
（２）複数の材料を用いることで、微小レンズ群に複雑な機能を持たせることが可能である。
【０３１４】
（３）用いる材料を適宜選択することで、任意の視認性を持たせることが可能である。
【０３１５】
請求項７に記載の発明によれば、請求項１乃至６の内いずれか１の効果に加え、
（１）保護膜により発光層が保護されているため、微小レンズ群を形成するための製造プロセスの選択肢が増加し、容易に微小レンズ群を形成することができる。
【０３１６】
（２）保護膜により発光層が保護されているため、微小レンズ群を形成するための材料の選択肢が増加し、容易に微小レンズ群を形成することができる。
【０３１７】
（３）保護膜により発光層が保護されているため、微小レンズ群を貼り付ける光学結合材の選択肢が増加し、容易に微小レンズ群を貼り付けることができる。
【０３１８】
（４）保護膜により発光層が保護されているため、微小レンズ群を貼り付ける光学結合材の塗布方法の選択肢が増加し、容易に微小レンズ群を貼り付けることができる。
【０３１９】
請求項８に記載の発明によれば、請求項７の効果に加え、
（１）全反射により微小レンズ群に到達できない光を減少させることができ、光の取り出し効率が向上する。
【０３２０】
（２）微小レンズ群に到達する光が増加するため、微小レンズ群の効果を有効にすることができ、光の取り出し効率が向上する。
【０３２１】
（３）発光層から放射される光が発光面の法線方向に立った配向となるため、素子内部での光損失を減少させることができ、視認性に優れた、高効率の発光性能を維持することができる。
【０３２２】
請求項９に記載の発明によれば、請求項７又は８の効果に加え、
（１）素子内部での光損失を減少させることができるため、視認性に優れた、高効率の発光性能を維持することができる。
【０３２３】
（２）素子内部での光損失が減少し、全反射により空気中へ取り出されない光が反射電極に反射され再利用することができるため、視認性に優れた、高効率の発光性能を維持することができる。
【０３２４】
請求項１０に記載の発明によれば、請求項３乃至９の内いずれか１の効果に加え、
（１）全反射により微小レンズ群に到達できない光を減少させることができ、光の取り出し効率が向上する。
【０３２５】
（２）微小レンズ群に到達する光が増加するため、微小レンズ群の効果を有効にすることができ、光の取り出し効率が向上する。
【０３２６】
（３）発光層から放射される光が発光面の法線方向に立った配向となるため、素子内部での光損失を減少させることができ、視認性に優れた、高効率の発光性能を維持することができる。
【０３２７】
請求項１１に記載の発明によれば、請求項３乃至１０の内いずれか１の効果に加え、
（１）素子内部での光損失を減少させることができるため、視認性に優れた、高効率の発光性能を維持することができる。
【０３２８】
（２）素子内部での光損失が減少し、全反射により空気中へ取り出されない光が反射電極に反射され再利用することができるため、視認性に優れた、高効率の発光性能を維持することができる。
【０３２９】
請求項１２に記載の発明によれば、請求項３乃至１１の内いずれか１の効果に加え、
（１）微小レンズ群と発光層の貼り付け時に光学結合材に適度な柔軟性があるため、微小レンズ群と発光層の表面部分の形状が異なっていても、容易に貼り付けることができる。
【０３３０】
（２）微小レンズ群と発光層の貼り付け時に光学結合材に適度な柔軟性があるため、容易に光学結合材を塗布することができる。
【０３３１】
（３）微小レンズ群と発光層の間の柔軟性があるため、折り曲げ等のストレスに対して強く、長期にわたって視認性に優れた高効率の発光性能を維持することができる。
【０３３２】
（４）微小レンズ群と発光層の間の柔軟性があるため、折り曲げ等のストレスに対して強く、可撓性のある素子を形成することが容易である。
【０３３３】
請求項１３に記載の発明によれば、請求項３乃至１２の内いずれか１の効果に加え、
（１）光学結合材の硬化に必要な熱あるいは光を適宜選択することにより、発光層にダメージを与えることなく容易に微小レンズ群と発光層とを貼り付けることができる。
【０３３４】
（２）光学結合材の硬化後は、微小レンズ群と発光層の位置関係が保持されるため、長期にわたって視認性に優れた高効率の発光性能を維持することができる。
【０３３５】
（３）光学結合材の厚さおよび材料を適宜選択することにより、折り曲げ等のストレスに対して強く、長期にわたって視認性に優れた高効率の発光性能を維持することができる。
【０３３６】
（４）光学結合材料の厚さおよび材料を適宜選択することにより、折り曲げ等のストレスに対して強く、可撓性のある素子を形成することが容易である。
【０３３７】
請求項１４に記載の発明によれば、請求項１乃至１３の内いずれか１の効果に加え、
（１）素子内部での光損失を減少させることができるため、長期に渡って高効率の発光性能を維持することができることができ、単純マトリックス方式での良好な照明を行うことができる。
【０３３８】
（２）陽極および陰極が、ストライプ状に個々電気的に分離されているので、画素における発光部を大きく取ることができる。
【０３３９】
（３）単純マトリックスの場合、瞬間的な高輝度が必要となるため、この高効率および発光部の大面積化は非常に重要である。
【０３４０】
請求項１５に記載の発明によれば、請求項１乃至１３の内いずれか１の効果に加え、この構成により、以下の作用が得られる。
【０３４１】
（１）素子内部での光損失を減少させることができるため、長期に渡って高効率の発光性能を維持することができることができ、アクティブマトリックス方式での良好な照明を行うことができる。
【０３４２】
（２）陽極又は陰極が、個々電気的に画素毎に分離されて構成されているので、瞬間的な高輝度は必要なく、実用上必要な輝度で良く、長期に渡って安定な発光を維持することができる。
【０３４３】
（３）陽極又は陰極は、少なくとも１つ以上のスイッチング素子を介して走査されるので、自由な画像形成が実現でき、有機エレクトロルミネッセンス素子の特徴である高速応答を十分に生かすことができる。
【０３４４】
（４）アクティブマトリックスの場合、画素内に配置されたスイッチング素子や配線等により発光部は凹凸面上に形成されることが多い。そのため、このような凹凸面上であっても高効率な発光の得られる施策は非常に有利である。
【０３４５】
請求項１６に記載の発明によれば、請求項１４又は１５の効果に加え、
（１）微小レンズ群を形成する微小レンズの直径を、画素の長辺よりも小さい構成とすることで、１つの画素内に少なくとも１つ以上の微小レンズを配置することができ、どの画素においても同様な取り出し効率向上効果が得られ、良好な画像を得ることができる。
【０３４６】
（２）発光部から微小レンズの頂上部分までの距離を小さくすることができるため、視認性に優れた、高効率の発光性能を維持することができる。
【０３４７】
請求項１７に記載の発明によれば、請求項１４乃至１６の内いずれか１の効果に加え、
（１）微小レンズ群を形成する微小レンズの直径を、画素の短辺よりも小さい構成とすることで、画素内に少なくとも１つ以上の微小レンズを密に配置することができ、どの画素においても同様な取り出し効率向上効果が得られ、良好な画像を得ることができる。
【０３４８】
（２）画素内に少なくとも１つ以上の微小レンズを密に配置することができ、どの画素においても指向性のない一様な光の取り出しが行われ、視認性に優れた良好な画像を得ることができる。
【０３４９】
（３）発光部から微小レンズの頂上部分までの距離を非常に小さくすることができるため、視認性に優れた、高効率の発光性能を維持することができる。
【０３５０】
請求項１８に記載の発明によれば、請求項１４乃至１７の内いずれか１の効果に加え、
（１）発光部から微小レンズ群の最表面までの距離が画素の長辺よりも小さいため、光にじみは画素長辺程度の広がりとなり、視認性に優れた、高効率の発光性能を維持することができる。
【０３５１】
（２）発光部から微小レンズ群の最表面までの距離が画素の長辺よりも小さいため、光の横方向への広がりは画素長辺程度となり、容易に光の再利用ができ、視認性に優れた、高効率の発光性能を維持することができる。
【０３５２】
請求項１９に記載の発明によれば、請求項１４乃至１８の内いずれか１の効果に加え、
（１）発光部から微小レンズ群の最表面までの距離が画素の短辺よりも小さいため、光にじみは画素短辺程度の広がりとなり、高精細で視認性に優れた、高効率の発光性能を維持することができる。
【０３５３】
（２）発光部から微小レンズ群の最表面までの距離が画素の短辺よりも小さいため、光の横方向への広がりは画素短辺程度となり、光の再利用効率が高く、視認性に優れた、高効率の発光性能を維持することができる。
【０３５４】
請求項２０に記載の発明によれば、請求項１４乃至１９の内いずれか１の効果に加え、
（１）素子内部での光損失を減少させることができるため、高効率の発光性能を維持することができることができ、電池容量等の減量化による、軽量化あるいは長使用時間化を図ることができる。
【０３５５】
（２）視覚特性（光の配向）を適当に設計することで、周囲からは見にくいプライベートウインドウや、複数人でも見やすいウインドウ等として用途に応じて用いることができる。
【０３５６】
（３）光取り出し面上の平坦化面の形成された表示手段を用いることで、微小レンズが直接表面に出ていないため、ほこり等のごみが付着しても、視認性に優れた高効率な画像表示を得ることができる。
【０３５７】
（４）光取り出し面上の平坦化面上に防汚フィルム等を容易に貼り付けることができるため、ほこり等のごみを容易に取り除くことができる。
【０３５８】
請求項２１に記載の発明によれば、
（１）簡単な工程で、長期に渡って発光性能を維持することができる有機エレクトロルミネッセンス素子を作成することができる。
【０３５９】
（２）形成方法が簡単なため、作業性が高く、生産性も高い。
【０３６０】
（３）真空一貫で形成することができるため、作業性が高く、生産性も高く、さらに、長期に安定な有機エレクトロルミネッセンス素子を作成することができる。
【０３６１】
請求項２２に記載の発明によれば、
（１）簡単な工程で、長期に渡って発光性能を維持することができる有機エレクトロルミネッセンス素子を作成することができる。
【０３６２】
（２）形成方法が簡単なため、作業性が高く、生産性も高い。
【０３６３】
（３）容易に密な微小レンズ群を形成することができ、高効率な有機エレクトロルミネッセンス素子を作成することができる。
【０３６４】
請求項２３に記載の発明によれば、
（１）簡単な工程で、長期に渡って発光性能を維持することができる有機エレクトロルミネッセンスを作成することができる。
【０３６５】
（２）形成方法が簡単なため、作業性が高く、生産性も高い。
という作用が得られる。
【０３６６】
請求項２４に記載の発明によれば、
（１）簡単な工程で、長期に渡って発光性能を維持することができる有機エレクトロルミネッセンスを作成することができる。
【０３６７】
（２）形成方法が簡単なため、作業性が高く、生産性も高い。
【０３６８】
請求項２５に記載の発明によれば、光取り出し面／空気界面の面積が増大し、界面における全反射の確率が低下し、光の取り出し効率が向上する。
【０３６９】
そして、視認性に優れた高効率な発光性能を維持することができる有機エレクトロルミネッセンス素子の提供、視認性の優れた、高効率の発光性能を維持することができる画像形成装置の提供、重量が軽く、使用時間の長い携帯端末、簡単な工程で形成でき、作業性が高く、生産性も高い有機エレクトロルミネッセンス素子の製造方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の実施の形態における有機エレクトロルミネッセンス素子の概略断面図
【図２】光学シミュレーションの結果を示すグラフ
【図３】実施の形態１における有機エレクトロルミネッセンス素子の要部断面図
【図４】実施の形態２における有機エレクトロルミネッセンス素子の要部断面図
【図５】実施の形態３における有機エレクトロルミネッセンス素子を用いた画像形成装置の概略斜視図
【図６】実施の形態４の有機エレクトロルミネッセンス素子を用いた携帯端末を示す斜視図
【図７】本発明の有機エレクトロルミネッセンス素子を用いた携帯端末を示すブロック図
【図８】従来の有機エレクトロルミネッセンス素子の要部断面図
【図９】従来の有機エレクトロルミネセンス素子の要部断面における代表的な光線経路を示す模式図
【符号の説明】
１ 基板
２ 陽極
３ 正孔輸送層
４ 発光層
５ 陰極
６ 微小レンズ群
７ 光学結合材
８ 保護膜
９ 発光層から放射された光の光源
１０ マイク
１１ スピーカー
１２ 操作部
１３ 表示部
１４ アンテナ
１５ 送信部
１６ 受信部
１７ 制御部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to various image forming apparatuses, light sources or backlights of image forming apparatuses, organic electroluminescent elements used for light emitting elements used in optical communication equipment, image forming apparatuses using the same, portable terminals, and The present invention relates to a method for manufacturing an organic electroluminescence element.
[0002]
[Prior art]
An electroluminescence element is a light-emitting device that utilizes electroluminescence of a solid fluorescent substance. Currently, inorganic electroluminescence using an inorganic material as a light emitter has been put into practical use, and is used for backlights and flat displays of liquid crystal displays. Some applications are being developed. However, inorganic electroluminescence requires a voltage as high as 100 V or higher to emit light, and it is difficult to emit blue light. Therefore, it is difficult to achieve full color using RGB three primary colors. Inorganic electroluminescence has a very large refractive index of the material used as a light emitter, so it is strongly influenced by total reflection at the interface, and the light extraction efficiency into the air for actual light emission is 10 to 20%. It is difficult to achieve high efficiency.
[0003]
On the other hand, research on electroluminescence using organic materials has been attracting attention for a long time, and various studies have been made. However, since the luminous efficiency is very low, full-scale practical research has not progressed.
[0004]
However, in 1987, Kodak's C.I. W. Tang et al. Proposed an organic electroluminescence device having a function-separated stacked structure in which an organic material is divided into two layers, a hole transport layer and a light-emitting layer, and 1000 cd / m despite a low voltage of 10 V or less. ² It became clear that the above high luminance can be obtained [C. W. Tang and S.M. A. Vanslyke: Appl. Phys. Lett, 51 (1987) 913, etc.]. Since then, organic electroluminescence elements have attracted a great deal of attention, and research on organic electroluminescence elements having a similar function-separated layered structure has been actively conducted, especially for the practical application of organic electroluminescence elements. In addition, high efficiency and long life which are indispensable for the use have been studied sufficiently, and in recent years, displays using organic electroluminescence elements have been manufactured.
[0005]
Here, the structure of the conventional general organic electroluminescent element is demonstrated using FIG.
[0006]
FIG. 8 is a cross-sectional view of a main part of a conventional organic electroluminescence element.
[0007]
In FIG. 8, 1 is a substrate made of glass or the like, 2 is an anode formed on the substrate 1, 3 is a hole transport layer formed on the anode 2, and 4 is formed on the hole transport layer 3. The light emitting layer 5 is a cathode formed on the light emitting layer 4.
[0008]
As shown in FIG. 8, the organic electroluminescence element includes an anode 2 made of a transparent conductive film such as ITO formed on a substrate 1 made of glass or the like by sputtering or resistance heating vapor deposition, and the like. From N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1, 1′-diphenyl-4, 4′-diamine (hereinafter referred to as TPD) formed by resistance heating vapor deposition or the like Hole transport layer 3, and 8-hydroxyquinoline aluminum (hereinafter referred to as Alq) formed on the hole transport layer 3 by resistance heating vapor deposition or the like. _Three And a cathode 5 made of a metal film having a thickness of 100 to 300 nm formed on the light emitting layer 4 by a resistance heating vapor deposition method or the like.
[0009]
When a direct current voltage or direct current is applied with the anode 2 of the organic electroluminescence element having the above configuration as a positive electrode and the cathode 5 as a negative electrode, holes are generated from the anode 2 to the light emitting layer 4 through the hole transport layer 3. Then, electrons are injected from the cathode 5 into the light emitting layer 4. In the light-emitting layer 4, recombination of holes and electrons occurs, and a light emission phenomenon occurs when excitons generated thereby shift from the excited state to the ground state.
[0010]
In such an organic electroluminescence device, light emitted from the phosphor in the light emitting layer 4 is normally emitted in all directions centering on the phosphor and passes through the hole transport layer 3, the anode 2, and the substrate 1. Alternatively, the light is once reflected in the direction opposite to the light extraction direction, reflected by the cathode 5, and radiated into the air via the light emitting layer 4, the hole transport layer 3, the anode 2, and the substrate 1. However, when light passes through the boundary surface of each medium, if the refractive index of the medium on the incident side is larger than the refractive index on the outgoing side, the angle at which the outgoing angle of the refracted wave becomes 90, that is, larger than the critical angle. Since light incident at an angle is totally reflected, it cannot pass through the boundary surface and is not extracted into the air.
[0011]
Here, the relationship between the refraction angle of light and the refractive index of the medium at the interface between different media follows Snell's law. According to Snell's law, the refractive index n ₁ Refractive index n from the medium of ₂ Incident light θ ₁ And refraction angle θ ₂ N ₁ sinθ ₁ = N ₂ sinθ ₂ The relationship becomes true. Therefore, n ₁ > N ₂ If θ holds, θ ₂ = Angle of incidence θ of 90 ° ₁ = Sin ^-1 (N ₂ / N ₁ ) Is well known as the critical angle, and when the incident angle is larger than this, the light is totally reflected at the interface between the media.
[0012]
Therefore, in an organic electroluminescence device that emits light isotropically, light emitted at an angle larger than the critical angle repeats total reflection at the boundary surface, is confined inside the device, and is emitted into the air. Disappear.
[0013]
FIG. 9 is a schematic view showing a typical light path in a cross section of a main part of a conventional organic electroluminescence element.
[0014]
In FIG. 9, as in FIG. 8, 1 is a substrate, 2 is an anode, 3 is a hole transport layer, 4 is a light emitting layer, 5 is a cathode, and 9 is a light source. As shown in FIG. 9, the light emitted from the light source 9 of the light emitted from the light emitting layer 4 is the interface between the anode 2 and the substrate 1 (ITO / glass interface), and the interface between the substrate 1 and air. When the refractive index of the medium on the incident side is larger than the refractive index on the outgoing side at each interface such as (glass / air interface), the outgoing angle of the refracted wave is larger than the critical angle. Since it is totally reflected, it cannot pass through the boundary surface and is not taken out into the air.
[0015]
This does not radiate light emitted from the light emitting layer to the outside of the device, and causes an apparent decrease in efficiency as an organic electroluminescence device. In general, most of the radiated light obtained from the light emitting layer of an organic electroluminescence device is confined inside the device by total reflection, and it is known that the effective radiated light is about 17% to 20%. [Refer to Advanced Material 6 (1994) 491 etc.].
[0016]
Thus, it has been proposed to solve the above-mentioned problems by providing means for converting the light emission angle on the substrate of the organic electroluminescence element.
[0017]
As a conventional organic electroluminescence element, Japanese Patent No. 2773720 discloses an “organic thin film electroluminescence element used for a light source such as a segment or a dot display”. An organic thin film electroluminescent device that improves extraction efficiency is described.
[0018]
Japanese Patent No. 2911183 discloses an “organic electroluminescence device having excellent luminous efficiency”, and an organic material having improved light extraction efficiency by forming a diffraction grating or the like at a position where total reflection at the device interface is suppressed. An electroluminescent element is described.
[0019]
Japanese Patent Application Laid-Open No. 9-129375 discloses an “organic electroluminescence element”, and an organic electroluminescence device in which the light extraction efficiency is improved by causing the irregular surface of the light extraction side or the reflection / refraction angle to be disturbed. A luminescence element is described.
[0020]
Japanese Patent Application Laid-Open No. 10-189251 discloses “a display device using an organic electroluminescence element” and describes that a means for converting a light emission angle is formed in a transparent substrate.
[0021]
Japanese Patent Application Laid-Open No. 10-308286 discloses an “organic electroluminescence element light emitting device suitably used for consumer and industrial display devices and color displays”, and forms a light reflecting layer on the side surface of the lower electrode. Thus, an organic electroluminescence element that improves light extraction efficiency is described.
[0022]
[Problems to be solved by the invention]
However, the conventional organic electroluminescence device has the following problems.
[0023]
(1) When used in an image forming apparatus such as a display, when the lens structure and the pixel correspond one-to-one, it is difficult to align the lens, and the problem is that visibility decreases due to misalignment. Had.
[0024]
(2) When used in an image forming apparatus such as a display, since the lens structure is on the light extraction surface side of the substrate surface, there is a problem that it is difficult to reduce the distance between the lens structure and the light emitting unit. .
[0025]
(3) When the lens structure is formed on the substrate, the light emitted from the organic electroluminescence element passes through both the lens structure and the substrate and is extracted into the air. This results in a problem that the light emission efficiency deteriorates.
[0026]
(4) When an organic electroluminescence element having a lens structure formed on a substrate is used as an image forming apparatus such as a display, light emitted from an arbitrary pixel passes through both the lens structure and the substrate and is extracted into the air. Therefore, the totally reflected light reaches another pixel via the substrate and is emitted from the pixel into the air, causing so-called stray light, and has a problem of causing a problem such as a decrease in contrast. It was.
[0027]
(5) When taking measures to improve the light extraction efficiency such as the mesa structure, it is necessary to reduce the area of the light emitting part, and it is necessary to design in consideration of the balance between the life and the efficiency, which is disadvantageous for extending the life. It had the problem that.
[0028]
(6) When taking measures to improve the light extraction efficiency such as the lens structure or mesa structure formed on the substrate side, it is difficult to design the light orientation freely, and the wide field of view that is characteristic of the organic electroluminescence device It has a problem that it causes a decrease in visibility such as angular characteristics.
[0029]
The present invention solves the above-described conventional problems, and provides an organic electroluminescence device capable of maintaining high-efficiency light-emitting performance with excellent visibility, and maintains high-light-emitting performance with high visibility. An object of the present invention is to provide an image forming apparatus that can be formed, a portable terminal that is light in weight, has a long use time, can be formed in a simple process, has high workability, and has high productivity. To do.
[0030]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an organic electroluminescence device of the present invention comprises an organic electroluminescence device comprising an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons on a substrate. A microlens group of elements, wherein light emitted from the light emitting layer is extracted from a light extraction surface facing the substrate, and is formed on the light extraction surface by at least two or more substantially hemispherical microlenses having different sizes. It consists of the structure which is formed.
[0031]
With this configuration, it is possible to provide an organic electroluminescence element that can maintain a long lifetime and high light emission performance.
[0032]
The image forming apparatus of the present invention is an organic electroluminescence device comprising an anode for injecting holes, a light-emitting layer having a light-emitting region, and a cathode for injecting electrons on a substrate. The emitted light is extracted from a light extraction surface facing the substrate, and an organic electroluminescence in which a microlens group composed of at least two substantially hemispherical microlenses having different sizes is formed on the light extraction surface. The anode and cathode of the element are individually electrically separated in stripes and have an image display arrangement composed of one or more pixels.
[0033]
With this configuration, it is possible to provide an image forming apparatus using an organic electroluminescence element capable of maintaining a long light emission performance with a long lifetime.
[0034]
The image forming apparatus of the present invention is an organic electroluminescence device comprising an anode for injecting holes, a light-emitting layer having a light-emitting region, and a cathode for injecting electrons on a substrate. The emitted light is extracted from a light extraction surface facing the substrate, and an organic electroluminescence in which a microlens group composed of at least two substantially hemispherical microlenses having different sizes is formed on the light extraction surface. The anode or cathode of the element is configured to be electrically separated for each pixel, and the separated electrode is scanned via at least one or more switching elements, thereby having an image display arrangement. Become.
[0035]
With this configuration, it is possible to provide an image forming apparatus using an organic electroluminescence element capable of maintaining a long light emission performance with a long lifetime.
[0036]
The portable terminal of the present invention includes a voice signal conversion unit that converts voice into a voice signal, an operation unit that inputs a telephone number, a display unit that displays an incoming call display and a telephone number, and a voice signal as a transmission signal. A mobile terminal comprising: a transmission unit that converts the received signal into a voice signal; an antenna that transmits and receives the transmission signal and the received signal; and a control unit that controls each unit. An organic electroluminescence device comprising an anode for injecting holes, a light-emitting layer having a light-emitting region, and a cathode for injecting electrons on a substrate, wherein light emitted from the light-emitting layer is light facing the substrate An anode of an organic electroluminescence device in which a microlens group consisting of at least two substantially hemispherical microlenses having different sizes is formed on the light extraction surface. And the cathode are individually electrically separated in stripes and have an image display arrangement of one or more pixels, or an anode for injecting at least holes on the substrate, and a light emitting layer having a light emitting region, An organic electroluminescence device having a cathode for injecting electrons, wherein light emitted from the light emitting layer is extracted from a light extraction surface facing the substrate, and has at least two different sizes on the light extraction surface The anode or cathode of the organic electroluminescence element in which a microlens group composed of substantially hemispherical microlenses is formed is electrically separated for each pixel, and the anode or cathode is at least one or more switching By scanning through the element, the image forming apparatus has an image display arrangement.
[0037]
With this configuration, it is possible to provide a portable terminal that is light in weight and long in use time.
[0038]
In addition, the method of manufacturing the organic electroluminescence element of the present invention includes forming an anode that injects at least holes, a light emitting layer having a light emitting region, and a cathode that injects electrons, and then in a device in a vacuum state. The microlens group is formed by spraying a thermosetting or photo-curing transparent resin in a mist form from below and curing it after turning the take-out surface downward.
[0039]
With this configuration, it is possible to provide a method for manufacturing an organic electroluminescence element that can be formed by a simple process, has high workability, and high productivity.
[0040]
In addition, the method for producing an organic electroluminescence device of the present invention is such that at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons are formed, and then the light extraction surface is covered with the surface. The spherical transparent beads of the amount are arranged and vibrated, the transparent beads are arranged in a dense state on the light extraction surface, a transparent resin having a low viscosity is poured, and then cured to form the micro lens group. It is composed of
[0041]
With this configuration, it is possible to provide a method for manufacturing an organic electroluminescence element that can be formed by a simple process, has high workability, and high productivity.
[0042]
In addition, the method for producing an organic electroluminescent element of the present invention includes forming an anode for injecting holes, a light-emitting layer having a light-emitting region, and a cathode for injecting electrons, and then forming a light-extraction surface thinner than transparent beads. Apply or stick a transparent resin with high viscosity, place spherical transparent beads in an amount that covers the surface, apply force uniformly, and form the micro lens group by applying extra beads. Consists of configuration.
[0043]
With this configuration, it is possible to provide a method for manufacturing an organic electroluminescence element that can be formed by a simple process, has high workability, and high productivity.
[0044]
In addition, in the method of manufacturing an organic electroluminescence element of the present invention, at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons are formed, and then a hemispherical microlens is formed. The microlens group is formed by applying or applying a uniform force to the sheet-like microlens group by applying or sticking a transparent resin.
[0045]
With this configuration, it is possible to provide a method for manufacturing an organic electroluminescence element that can be formed by a simple process, has high workability, and high productivity.
[0166]
[ BEST MODE FOR CARRYING OUT THE INVENTION ]
Hereinafter, the organic electroluminescence element in the embodiment of the present invention will be described in detail. First, the structure of the organic electroluminescent element in embodiment of this invention is demonstrated.
[0167]
FIG. 1 is a schematic cross-sectional view of an organic electroluminescence element in an embodiment of the present invention. In FIG. 1, 1 is a substrate, 2 is an anode, 4 is a light emitting layer, 5 is a cathode, 6 is a micro lens group, 6a is a planarized surface, and 7 is an optical coupling material. In FIG. 1, the side facing the substrate 1 is a light extraction surface.
[0168]
The micro lens group 6 is formed on the light extraction surface (in this case, the anode 2) as shown in FIG. The individual microlenses constituting the microlens group 6 are substantially hemispherical and may have any structure that arbitrarily changes the angle of light at the interface with air or extracts light. Various forms can be taken. In the present invention, the hemisphere is not limited to a half of a sphere, and includes, for example, a three-dimensional structure obtained by cutting a sphere or an elliptic sphere, such as a 1/3 sphere or a 3/5 sphere. Needless to say.
[0169]
The microlenses constituting the microlens group 6 may be the same size as each other. However, by making the sizes different from each other, the microlenses 6 can be randomly arranged with no gap on the light extraction surface. It is possible to contribute to improvement of light extraction efficiency at an arbitrary position on the extraction surface. Furthermore, a scattering effect can also be imparted.
[0170]
In addition, if the microlenses constituting the microlens group 6 have different sizes, a simple forming method by spraying a polymer material or the like can be used to form the microlens group 6, and in particular, In the case where the lens group 6 is formed on the micron order, it is preferable because strict management such as dimensional accuracy is unnecessary and manufacturing is easy.
[0171]
Furthermore, as shown in FIG. 1B, the micro lens group 6 may be formed on the light extraction surface (in this case, the cathode 5) via an optical coupling material 7. The optical coupling material 7 is a member that optically couples the micro lens group 6 and the light extraction surface.
[0172]
As another form of the micro lens group 6, as shown in FIG. 1C, the surface of the micro lens group 6 is flat on the light extraction surface side of the micro lens group 6 through an air layer and some contacts. The structure provided with the planarization surface 6a may be sufficient. The flattened surface 6a is configured so that the minute lens group 6 is not directly exposed to the outside. The flattened surface 6a can protect the micro lens group 6 and is a flat surface, and therefore, processing on the surface is further facilitated.
[0173]
As shown in FIGS. 1A to 1C, the cathode 5 is formed on the substrate 1 and the anode 2 is formed through the light emitting layer 4, or the anode 2 is formed on the substrate 1. Although any configuration in which the cathode 5 is formed via the light emitting layer 4 may be used, the anode 2 or the cathode 5 formed on the light extraction surface side is a transparent electrode. In order to improve the light extraction efficiency, the electrode formed on the substrate 1 side is preferably formed of a material that reflects light.
[0174]
Next, each structure of the organic electroluminescence element in the embodiment of the present invention will be described in detail including materials.
[0175]
First, the micro lens group will be described. The micro lens group is composed of at least two substantially hemispherical micro lenses of different sizes, and may be any structure that arbitrarily changes the angle of light at the interface with air or extracts light, and is formed on the light extraction surface. It only has to be done. Materials for the micro lens group include transparent or translucent soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz glass, inorganic oxide glass, inorganic Inorganic glass such as fluoride glass, or transparent or translucent polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyether sulfone, polyvinyl fluoride, polypropylene, polyethylene, polyacrylate, amorphous polyolefin, fluorine resin, etc. Polymer film, etc., or transparent or translucent As ₂ S _Three , As ₄₀ S _Ten , S ₄₀ Ge _Ten Such as chalcogenoid glass, ZnO, Nb ₂ O _Five , Ta ₂ O _Five , SiO, Si _Three N _Four , HfO ₂ TiO ₂ It can be used by appropriately selecting from transparent materials such as materials such as metal oxides and nitrides. In addition, as a material of the micro lens group, it can be used by appropriately selecting from transparent or semi-transparent materials among the substrate materials to be described later, and further, optical adhesive such as transparent resist material, ultraviolet curing type, thermosetting type An agent or a transparent material in which they are combined can also be used.
[0176]
The optical coupling material is a member that optically couples the minute lens group and the light extraction surface, and preferably has a refractive index equal to or larger than either the minute lens group or the light extraction surface. As a material of this optical coupling material, a material having sufficient flexibility and adhesiveness among transparent or translucent substrate materials among the substrate materials described later can be used.
[0177]
The flattening surface may be a flattening film whose surface is flattened on the light extraction surface side of the microlens group via an air layer and some contacts, and the microlens group is directly exposed to the outside. Any configuration that is not required is acceptable. As a material for the planarizing film, either a transparent or semi-transparent substrate material, which will be described later, can be used, and since it is a member that is directly exposed to the outside, it has sufficient strength or flexibility. It can be used by appropriately selecting from materials.
[0178]
Here, based on the layer configuration of the organic electroluminescence element shown in FIG. 1A, an optical simulation was performed regarding the light extraction efficiency when the refractive index of the microlens group was changed.
[0179]
FIG. 2 shows the result of this optical simulation. FIG. 2 is a graph showing the result of optical simulation.
[0180]
Here, the conditions of the optical simulation will be specifically described. The refractive index of each layer is the light emitting layer = 1.7, the anode is ITO = 2.0, the air is 1.0, and the film thickness of each layer is the light emitting layer = 150 nm, ITO = 150 nm, the diameter of the micro lens group = 50 μm. Further, in this simulation, (a) a case where a micro lens group is provided (air / micro lens group / ITO / light emitting layer / cathode / substrate), and (b) a case where no micro lens group is provided (air / ITO / light emitting layer / cathode). The simulation was performed for two cases. In this simulation, the light extraction efficiency when the refractive index of the micro lens group in (a) was changed was obtained as a relative value to the light extraction efficiency in (b). That is, in FIG. 2, the horizontal axis indicates the refractive index, and the vertical axis indicates the ratio of the light extraction efficiency between (a) and (b) = (a) / (b).
[0181]
Note that all light from the light emitting layer is reflected at the interface between the light emitting layer and the cathode, and only absorption in the light emitting layer and ITO is considered. That is, the reflectance of the cathode is 100%, and the transmittances of the light emitting layer, ITO, and the microlens group are 80%, 97%, and 97%, respectively. Here, the simulation was performed with the refractive index of the micro lens group = 1.3, 1.5, 1.7, 1.9.
[0182]
Under the above conditions, the refractive index of the microlens group becomes large as is apparent from the result of this simulation in which the ratio of the extraction efficiency when the refractive index of the microlens group is changed as shown in FIG. As the value increases, the relative value of the extraction efficiency increases. Specifically, when the value of the refractive index is 1.4 or more, the relative value of the light extraction efficiency increases, and has a maximum inflection point in the vicinity of 1.7. Although a slight decrease is observed in a region larger than that, even in this case, the efficiency is about 1.8 times. As described above, the light extraction efficiency is improved when the refractive index of the minute lens group is large, and the refractive index of the minute lens group is preferably 1.4 or more. Needless to say, this includes a flattened surface constituting the micro lens group, but the same applies to the optical coupling material formed on the light extraction surface and a protective film described later. .4 or more is preferable.
[0183]
Next, the substrate will be described. Since the substrate is not used as a light extraction surface, either a transparent or opaque substrate can be used as long as it has a strength capable of holding the organic electroluminescence element. Substrate materials include transparent or translucent soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz glass, etc., inorganic oxide glass, inorganic fluoride Inorganic glass such as glass, or polymers such as transparent or translucent polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyether sulfone, polyvinyl fluoride, polypropylene, polyethylene, polyacrylate, amorphous polyolefin, fluorine resin, etc. Film, etc., or transparent or translucent As ₂ S _Three , As ₄₀ S _Ten , S ₄₀ Ge _Ten Such as chalcogenoid glass, ZnO, Nb ₂ O _Five , Ta ₂ O _Five , SiO, Si _Three N _Four , HfO ₂ TiO ₂ Insulating treatment is performed on the surface of the transparent substrate material containing pigments and the like, or materials such as metal oxides and nitrides such as opaque materials, semiconductor materials such as opaque silicon, germanium, silicon carbide, gallium arsenide, and gallium nitride. It can be used by appropriately selecting from the applied metal material or the like, and a laminated substrate in which a plurality of substrate materials are laminated can also be used. A circuit composed of a resistor, a capacitor, an inductor, a diode, a transistor, or the like for driving the organic electroluminescence element may be formed on the substrate surface or inside the substrate.
[0184]
The anode is an electrode for injecting holes, and it is necessary to efficiently inject holes into the light emitting layer or the hole transport layer. A transparent electrode can be used as the anode. Transparent electrode materials include indium tin oxide (ITO) and tin oxide (SnO). ₂ ), A metal oxide such as zinc oxide (ZnO), a transparent conductive film made of a mixture such as SnO: Sb (antimony), ZnO: Al (aluminum), or Al (thickness not to impair transparency). A metal thin film such as aluminum), Cu (copper), Ti (titanium), or Ag (silver), a metal thin film such as a mixed thin film or a laminated thin film of these metals, or a conductive polymer such as polypyrrole can be used. . Moreover, it can also be set as a transparent electrode by laminating | stacking several said transparent electrode material, It forms by various polymerization methods, such as resistance heating vapor deposition, electron beam vapor deposition, a sputtering method, or an electric field polymerization method. Further, it is desirable that the transparent electrode has a thickness of 1 nm or more in order to provide sufficient conductivity or to prevent uneven light emission due to unevenness on the substrate surface. In addition, it is desirable that the thickness be 500 nm or less in order to provide sufficient transparency. Furthermore, as the anode, besides the transparent electrode, a metal having a large work function such as Cr (chromium), Ni (nickel), Cu (copper), Sn (tin), W (tungsten), Au (gold), Alternatively, an alloy, oxide, or the like can be used, and a laminated structure of a plurality of materials using these anode materials can also be used. However, when the anode is not formed on the light extraction surface side, the anode is preferably formed of a material that reflects light in order to make the best use of the effect of the minute lens group. In that case, the cathode may be a transparent electrode.
[0185]
Further, an amorphous carbon film may be provided on the anode. In this case, both have a function as a hole injection electrode. That is, holes are injected from the anode into the light emitting layer or the hole transport layer through the amorphous carbon film. The amorphous carbon film is formed by sputtering between the anode and the light emitting layer or the hole transport layer. Examples of the carbon target by sputtering include isotropic graphite, anisotropic graphite, glassy carbon, and the like. Although not particularly limited, isotropic graphite having high purity is suitable. Specifically, when the work function of the amorphous carbon film is measured using a surface analyzer AC-1 manufactured by Riken Keiki, the work of the amorphous carbon film is shown. The function is W _C = 5.40 eV. Here, the work function of ITO, which is generally used as an anode, is W _ITO = 5.05 eV, it is possible to inject holes into the light emitting layer or the hole transport layer more efficiently by using the amorphous carbon film. Further, when the amorphous carbon film is formed by sputtering, reactive sputtering is performed in an atmosphere of nitrogen or a mixed gas of hydrogen and argon in order to control the electric resistance value of the amorphous carbon film. Furthermore, in the thin film formation technique by sputtering or the like, when the film thickness is 5 nm or less, the film becomes an island structure and a uniform film cannot be obtained. For this reason, when the film thickness of the amorphous carbon film is 5 nm or less, efficient light emission cannot be obtained, and the effect of the amorphous carbon film cannot be expected. Further, when the film thickness of the amorphous carbon film is 200 nm or more, the color of the film becomes dark and light emitted from the organic electroluminescence element cannot be sufficiently transmitted.
[0186]
Further, the light emitting layer is preferably made of a phosphor having a fluorescent property in the visible region and having a good film forming property. _Three And Be-benzoquinolinol (BeBq ₂ ), 2,5-bis (5,7-di-t-pentyl-2-benzoxazolyl) -1,3,4-thiadiazole, 4,4′-bis (5,7-bentyl- 2-Benzoxazolyl) stilbene, 4,4′-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxazolyl] stilbene, 2,5-bis (5,7 -Di-t-benzyl-2-benzoxazolyl) thiophine, 2,5-bis ([5-α, α-dimethylbenzyl] -2-benzoxazolyl) thiophene, 2,5-bis [5, 7-di- (2-methyl-2-butyl) -2-benzoxazolyl] -3,4-diphenylthiophene, 2,5-bis (5-methyl-2-benzoxazolyl) thiophene, 4, 4′-bis (2-benzoxazolyl) biphenyl, 5-methyl-2- [2 Benzoxazoles such as-[4- (5-methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazolyl, 2- [2- (4-chlorophenyl) vinyl] naphtho [1,2-d] oxazole Benzothiazoles such as 2,2 '-(p-phenylenedivinylene) -bisbenzothiazole, 2- [2- [4- (2-benzimidazolyl) phenyl] vinyl] benzimidazole, 2- [2- ( 4-carboxyphenyl) vinyl] benzimidazole and other fluorescent whitening agents, bis (8-quinolinol) magnesium, bis (benzo-8-quinolinol) zinc, bis (2-methyl-8-quinolinolate) Aluminum oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) a 8 such as luminium, 8-quinolinol lithium, tris (5-chloro-8-quinolinol) gallium, bis (5-chloro-8-quinolinol) calcium, poly [zinc-bis (8-hydroxy-5-quinolinyl) methane] -Metal chelated oxinoid compounds such as hydroxyquinoline-based metal complexes and dilithium ependridione, 1,4-bis (2-methylstyryl) benzene, 1,4- (3-methylstyryl) benzene, 1,4 -Bis (4-methylstyryl) benzene, distyrylbenzene, 1,4-bis (2-ethylstyryl) benzene, 1,4-bis (3-ethylstyryl) benzene, 1,4-bis (2-methylstyryl) ) Styrylbenzene compounds such as 2-methylbenzene, 2,5-bis (4-methylstyryl) pyrazine, 2, -Bis (4-ethylstyryl) pyrazine, 2,5-bis [2- (1-naphthyl) vinyl] pyrazine, 2,5-bis (4-methoxystyryl) pyrazine, 2,5-bis [2- (4 -Biphenyl) vinyl] pyrazine, distil pyrazine derivatives such as 2,5-bis [2- (1-pyrenyl) vinyl] pyrazine, naphthalimide derivatives, perylene derivatives, oxadiazole derivatives, aldazine derivatives, A cyclopentadiene derivative, a styrylamine derivative, a coumarin derivative, an aromatic dimethylidin derivative, or the like is used. Furthermore, anthracene, salicylate, pyrene, coronene and the like are also used. Alternatively, a phosphorescent material such as fac-tris (2-phenylpyridine) iridium may be used.
[0187]
In addition to the single-layer structure of only the light-emitting layer, any of a two-layer structure of a hole transport layer and a light-emitting layer or a light-emitting layer and an electron transport layer, or a three-layer structure of a hole transport layer, a light-emitting layer, and an electron transport layer The structure of may be sufficient. However, in the case of such a two-layer structure or a three-layer structure, the hole transport layer and the anode are stacked or the electron transport layer and the cathode are in contact with each other.
[0188]
As the hole transport layer, those having high hole mobility, transparent and good film forming properties are preferable. Besides TPD, porphyrin compounds such as porphine, tetraphenylporphine copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, 1,1-bis {4- (di-P-tolylamino) phenyl} cyclohexane, 4,4 ′, 4 ″ -trimethyltriphenylamine, N, N, N ′, N′-tetrakis (P-tolyl) -P-phenylenediamine, 1- (N, N-di-P-tolylamino) naphthalene, 4,4 ′ -Bis (dimethylamino) -2-2'-dimethyltriphenylmethane, N, N, N ', N'-tetraphenyl-4,4'-diaminobiphenyl, N, N'-diphenyl-N, N'- Di-m-tolyl-4, N, N-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-4,4′-diamine, 4′-diaminobiphenyl, N Aromatic tertiary amines such as -phenylcarbazole, 4-di-P-tolylaminostilbene, 4- (di-P-tolylamino) -4 '-[4- (di-P-tolylamino) styryl ] Stilbene compounds such as stilbene, triazole derivatives, oxazizazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, annealed amine derivatives, amino-substituted chalcone derivatives, Oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, polysilane aniline copolymers, polymer oligomers, styrylamine compounds, aromatic dimethylidin compounds, poly 3- Organic such as methylthiophene Material is used. Further, a polymer-dispersed hole transport layer in which an organic material for a low-molecular hole transport layer is dispersed in a polymer such as polycarbonate is also used.
[0189]
As the electron transport layer, oxadiazole derivatives such as 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7), anthraquinodimethane derivatives, diphenylquinone Derivatives and the like are used.
[0190]
The cathode is an electrode for injecting electrons, and it is necessary to efficiently inject electrons into the light emitting layer or the electron transport layer, and Al (aluminum), In (indium), Mg (magnesium) having a small work function. In general, metals such as Ti (titanium), Ag (silver), Ca (calcium), and Sr (strontium), oxides or fluorides of these metals, alloys thereof, and laminates are generally used. Further, when the cathode is not formed on the light extraction surface side, the cathode is preferably formed of a material that reflects light in order to make the best use of the effect of the minute lens group. When a microlens group is formed, it is difficult to effectively suppress total reflection for all light. Therefore, among the light that has once reached the microlens group, the light that has not been extracted into the air The light is totally reflected at the interface with air, propagates again into the device, and reaches the cathode. Alternatively, since light is emitted isotropically in the light emitting layer, half of the light emitted from the light emitting layer reaches the cathode before reaching the light extraction surface. At this time, if the cathode is made of a material that reflects light, the light that reaches the cathode is reflected and can propagate again in the direction of the light extraction surface, which can be used as effective light. There is. In order to make this effect effective, the cathode is preferably formed of a material that reflects light, and the light reflectance is preferably 50% or more. This is because the efficiency improvement rate by the micro lens group is about twice, so that effective light extraction can be performed if the light reflectance is 50% or more, that is, the light loss at the cathode is 50% or less. Conventional organic electroluminescence elements are required to have a very high reflectance of the cathode. However, by improving the light extraction efficiency, the selectivity of the cathode material, film thickness, formation method, etc. can be expanded. . The above applies to the anode when the cathode is formed on the light extraction surface side as a transparent electrode.
[0191]
The cathode is formed as a transparent cathode by forming an ultra-thin film using a metal having a small work function at the interface contacting the light emitting layer or the electron transport layer and laminating a transparent electrode on the thin film. You can also. In particular, Mg, Mg—Ag alloy having a small work function, Al—Li alloy, Sr—Mg alloy, Al—Sr alloy, Al—Ba alloy, etc. described in JP-A-5-121172, or LiO ₂ A laminated structure such as / Al or LiF / Al is suitable as a cathode material.
[0192]
Furthermore, resistance heating vapor deposition, electron beam vapor deposition, and sputtering are used as a method for forming these cathodes.
[0193]
Thus, at least one of the anode and the cathode may be a transparent electrode. Furthermore, both may be transparent electrodes, but in order to improve the light extraction efficiency, if one is a transparent electrode, it is preferable that the other be formed of a material that reflects light.
[0194]
In addition, the transparency or semi-transparency of the material which comprises the organic electroluminescent element in this invention shows transparency of the grade which does not prevent the visual recognition of the light emission by an organic electroluminescent element.
[0195]
In addition, a protective film is formed on the anode or cathode formed on the light extraction surface side as necessary in order to shield the organic electroluminescence element from the outside air and ensure long-term stability. You may protect a laminated body so that it may wrap on a board | substrate. That is, it is preferable for long-term reliability to provide a protective film in order to suppress oxidation of the material and reaction with moisture. As the material of the protective film, SiON, SiO, SiN, SiO ₂ , Al ₂ O _Three , Thin films made of inorganic oxides such as LiF, inorganic nitrides, inorganic fluorides, glass films made of inorganic oxides, inorganic nitrides, inorganic fluorides, etc., thermosetting, photocurable resins, etc. Examples thereof include a silane polymer material having a sealing effect and the like, and it is formed by vapor deposition, sputtering, or a coating method. In the case where a protective film is provided, the micro lens group is formed on the protective film, but is formed via an optical coupling material as necessary.
[0196]
Next, the use of the organic electroluminescence device of the present invention will be described. The organic electroluminescence element of the present invention can be used as an image forming apparatus for displaying an image, and these image forming apparatuses include a display of a portable information terminal such as a mobile phone, a PHS, and a PDA, a television, a personal computer, and a car navigation system. It can be used for a display of AV equipment such as a stereo and a radio.
[0197]
Further, it can be used in an illumination device as a light source such as a laser printer or a scanner. Or it can also be used as a lighting device as a simple light source such as a lighting fixture such as a room lamp or a light stand.
[0198]
Among these, in consideration of advantages such as low power consumption, light weight and thinning of organic electroluminescence elements, and high response speed, image forming apparatuses and lasers as displays for displaying images in various electronic devices It is preferably used for an illumination device as a light source such as a printer or a scanner.
[0199]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0200]
(Embodiment 1)
The organic electroluminescent element in Embodiment 1 of this invention is described.
[0201]
FIG. 3 is a cross-sectional view of a main part of the organic electroluminescence element in the first embodiment.
[0202]
In FIG. 3, 1 is a substrate, 2 is an anode 2 formed on the substrate 1, 3 is a hole transport layer formed on the substrate 2, 4 is formed on the hole transport layer 3, and has a light emitting region. The light emitting layer 5 is a cathode formed on the light emitting layer 4, and 6 is a microlens group formed on the cathode 1.
[0203]
The organic electroluminescence element according to the first embodiment includes a cathode 5 on the side facing the substrate 1 as a transparent electrode, and a microlens group 6 on the surface of the cathode 5 as means for improving light extraction efficiency. The micro lens group 6 converts the angle of the light emitted from the light emitting layer into an arbitrary angle at the boundary surface between the light extraction surface and the air, or extracts the light into the air.
[0204]
In the first embodiment, the constituent material and the forming method described above can be used as the constituent material and the forming method of the organic electroluminescence element. Other conventionally known materials may be used.
[0205]
Furthermore, in the first embodiment, the case of a two-layer structure including the hole transport layer 3 and the light emitting layer 4 has been described. However, the structure is not particularly limited as described above. That is, a single-layer structure of only the light-emitting layer 4, a two-layer structure of the hole transport layer 3 and the light-emitting layer 4, or a light-emitting layer 4 and an electron transport layer, or a three-layer structure of the hole transport layer 3, the light-emitting layer 4, and the electron transport layer A structure may be sufficient as long as it has a light emitting layer 4 having a light emitting region between at least two electrodes of the anode 2 and the cathode 5.
[0206]
In the first embodiment, the structure in which the anode 2 is formed on the upper surface of the substrate 1 has been described. However, the structure is not particularly limited as described above, and the cathode 5 is formed on the upper surface of the substrate 1. May be formed.
[0207]
In addition, the sealing form can be formed by adhering the glass cap with a UV curable resin or the like so that the light extraction surface and the glass cap are not in close contact with each other, or a protective film is formed on the surface of the organic electroluminescence element. Appropriate means such as forming and sealing can be employed. In addition, a combination of a protective film and a shielding material may be used.
[0208]
As described above, according to the first embodiment, light can be extracted efficiently, so that highly efficient light emission performance can be maintained.
[0209]
The organic electroluminescent element in Embodiment 1 can be used as a lighting device or an image forming apparatus.
[0210]
(Embodiment 2)
An organic electroluminescence element according to Embodiment 2 of the present invention will be described.
[0211]
FIG. 4 is a cross-sectional view of a main part of the organic electroluminescence element in the second embodiment.
[0212]
In FIG. 4, 1 is a substrate, 2 is an anode, 3 is a hole transport layer, 4 is a light emitting layer, and 5 is a cathode. Reference numeral 6 denotes a microlens group composed of a microlens and a flattened surface 6a, 8 is a protective film formed on the cathode 5, and 7 is an optical coupling material for attaching the protective film 8 and the microlens group 6. It is.
[0213]
The organic electroluminescence element according to the second embodiment has a cathode 5 on the side facing the substrate 1 as a transparent electrode, and a protective film 8 is formed on the upper surface to shield it from moisture and reactive gas in the outside air. A microlens group 6 composed of a microlens and a flattened surface 6a is attached to the surface of the film 8 via an optical coupling material 7 as a means for improving the light extraction efficiency. The angle of the light emitted from 4 is converted to an arbitrary angle at the boundary surface between the light extraction surface and the air, or is extracted into the air.
[0214]
In the second embodiment, the constituent material and the forming method of the organic electroluminescence element may be the above-described constituent material, the forming method, or a conventionally known one.
[0215]
Further, in the second embodiment, the case of the two-layer structure including the hole transport layer 3 and the light emitting layer 4 has been described. However, the structure is not particularly limited as described above.
[0216]
In the second embodiment, the structure in which the anode 2 is formed on the upper surface of the substrate 1 has been described. However, the structure is not particularly limited as described above, and the cathode 5 is formed on the upper surface of the substrate 1. May be formed.
[0217]
In the second embodiment, as for the sealing mode, the protective film 8 is formed on the surface of the organic electroluminescence element for sealing, but the micro lens group 6 itself has a shielding property. Or the like.
[0218]
As described above, according to the second embodiment, light can be extracted efficiently, so that highly efficient light emission performance can be maintained.
[0219]
The organic electroluminescent element in Embodiment 2 can be used as a lighting device or an image forming apparatus.
[0220]
(Embodiment 3)
An image forming apparatus using an organic electroluminescence element according to Embodiment 3 of the present invention will be described.
[0221]
FIG. 5 is a schematic perspective view of an image forming apparatus using the organic electroluminescence element in the third embodiment. In FIG. 5, 1 is a substrate, 2 is an anode, 3 is hole transport, 4 is a light emitting layer, 5 is a cathode, 6 is a microlens group, and 7 is an optical coupling material.
[0222]
In the third embodiment, as shown in FIG. 3, the anode 2 is linearly patterned, and the cathode 5 is similarly linearly patterned in a form substantially perpendicular to the anode 2.
[0223]
If the anode 2 of this image forming apparatus is on the positive side and the cathode 5 is on the negative side and connected to a drive circuit (driver) as drive means (not shown), a DC voltage or a DC current is applied to the selected anode 2 and cathode 5. The light emitting layer 4 in the orthogonal part emits light and can be used as a simple matrix type image forming apparatus.
[0224]
In the third embodiment, a minute lens group 6 formed in a sheet shape as light angle conversion means is attached to the element forming surface of the substrate 1 via an optical coupling material 7. The micro lens group 6 converts the angle of light emitted from the light emitting layer 4 to an arbitrary angle at the interface with air, or is taken out into the air at the interface with air. It is like that. The micro lens group 6 is a sheet-like micro lens group formed by combining a sheet serving as a housing and a micro lens.
[0225]
In the third embodiment, the constituent material and the forming method of the organic electroluminescence element are not limited to this, and the above-described constituent material, the forming method, and a conventionally known one may be used.
[0226]
As described above, in the image forming apparatus according to Embodiment 3, light can be extracted efficiently, so that the light extraction efficiency is improved and high-efficiency light emission performance can be maintained. In addition, since the distance from the light emitting layer 4 to the micro lens group 6 is smaller than the short side direction of the pixel, it is possible to suppress the light propagation in the lateral direction on the light extraction surface, and to maintain a highly efficient light emitting performance. In addition to being able to do so, there is no light blur or the like, and visibility is improved.
[0227]
In the third embodiment, the simple matrix type image forming apparatus has been described. However, an active matrix type image forming apparatus may be used, and the same high-efficiency light-emitting performance as that of the simple matrix type can be maintained. it can.
[0228]
Note that the image forming apparatus according to Embodiment 3 can be used not only as an image forming apparatus that displays an image but also as an illumination device such as a light source such as a laser printer or a scanner. Further, the anode 2 and the cathode 5 may be used as a simple lighting device by emitting light over the entire surface without patterning them linearly.
[0229]
(Embodiment 4)
A portable terminal using the organic electroluminescence element of Embodiment 4 of the present invention will be described.
[0230]
FIG. 6 is a perspective view showing a portable terminal using the organic electroluminescence element of Embodiment 4, and FIG. 7 is a block diagram showing the portable terminal using the organic electroluminescence element of the present invention.
[0231]
6 and 7, reference numeral 10 denotes a microphone that converts voice into an audio signal, 11 denotes a speaker that converts the voice signal into voice, 12 denotes an operation unit including dial buttons, and 13 denotes a display unit that displays an incoming call or the like. It is composed of an image forming apparatus using the organic electroluminescence element of the present invention, 14 is an antenna, 15 is a transmission unit that converts an audio signal from the microphone 10 into a transmission signal, and is created by the transmission unit 15 The transmission signal is emitted to the outside through the antenna 14. Reference numeral 16 denotes a receiving unit that converts a received signal received by the antenna 14 into an audio signal. The audio signal created by the receiving unit 16 is converted into audio by the speaker 11. A control unit 17 controls the transmission unit 15, the reception unit 16, the operation unit 12, and the display unit 13.
[0232]
The microphone 10 receives the voice of the user (sender) during a call, and the other party's voice or notification sound is output from the speaker 11 and transmitted to the user (receiver). Note that in the case where a pager is used as the portable terminal, the microphone is not particularly required.
[0233]
Furthermore, the operation unit 12 includes a numeric keypad as a dial button and various function keys. Moreover, not only a numeric keypad and various function keys but a character key etc. may be provided. From the operation unit 12, predetermined data such as a telephone number, name, time, setting of various functions, an e-mail address, and a URL are input. Further, the operation unit 12 may use not only the keyboard operation but also a pen input device, a voice input device, a magnetic or optical input device.
[0234]
The display unit 13 displays predetermined data input from the operation unit 12, data such as a telephone number, an e-mail address, a URL, or a character icon stored in a memory.
[0235]
The antenna 14 performs at least one of transmission and reception of radio waves. Note that in this embodiment mode, transmission and reception of signals are performed by radio waves, and thus antennas (helical antennas, planar antennas, etc.) are provided. It may be provided instead. In this case, the light emitting element transmits a signal to another communication device or the like, and the light receiving element receives an external signal.
[0236]
The transmission unit 15 and the reception unit 16 each convert an audio signal into a transmission signal, and convert the received reception signal into an audio signal.
[0237]
Further, the control unit 17 is configured by a conventionally known method using a CPU, a memory, or the like not shown, and controls the transmission unit 15, the reception unit 16, the operation unit 12, and the display unit 13. More specifically, a command is given to each control circuit, drive circuit, etc. (not shown) provided in each of these units. For example, the display control circuit that has received a display command from the control unit 17 drives the display drive circuit and displays on the display unit 13.
[0238]
The operation will be described below.
[0239]
First, when there is an incoming call, the receiving unit 16 sends an incoming signal to the control unit 17, and the control unit 17 displays a predetermined character or the like on the display unit 13 based on the incoming signal, and further performs an operation. When a button or the like for receiving an incoming call from the unit 12 is pressed, a signal is sent to the control unit 17, and the control unit 17 sets each unit in the incoming mode. That is, the signal received by the antenna 14 is converted into an audio signal by the receiving unit 16, the audio signal is output as audio from the speaker 11, and the audio input from the microphone 10 is converted into an audio signal, and the transmitting unit 15 And is transmitted to the outside through the antenna 14.
[0240]
Next, the case of making a call will be described.
[0241]
First, when making a call, a signal indicating that the call is sent from the operation unit 12 is input to the control unit 17. Subsequently, when a signal corresponding to the telephone number is sent from the operation unit 12 to the control unit 17, the control unit 17 sends a signal corresponding to the telephone number from the antenna 14 via the transmission unit 15. When communication with the other party is established by the transmission signal, when a signal to that effect is sent to the control unit 17 through the reception unit 16 via the antenna 14, the control unit 17 sets each unit to the transmission mode. That is, the signal received by the antenna 14 is converted into an audio signal by the receiving unit 16, the audio signal is output as audio from the speaker 11, and the audio input from the microphone 10 is converted into an audio signal, and the transmitting unit 15 And is transmitted to the outside through the antenna 14.
[0242]
In the fourth embodiment, an example in which voice is transmitted and received is shown. However, the same effect is obtained not only for voice but also for a mobile terminal that transmits and / or receives data other than voice, such as character data. be able to.
[0243]
In such a portable terminal according to Embodiment 4, it is possible to maintain high-efficiency light-emitting performance, and thus it is possible to suppress the amount of power used by a battery or the like. This makes it possible to use the portable terminal for a long time, or to reduce the weight by reducing the size of the battery. In particular, in recent years, display elements used in portable terminals have been required to have higher image quality and lower power consumption, and higher image quality and higher efficiency compared with conventional light extraction of organic electroluminescence elements are significant advantages. Bring. High efficiency makes it possible to reduce the battery capacity, thereby reducing the weight and extending the usage time. In addition, if a polymer film is used as the substrate of the organic electroluminescence element, it is possible to bring about a dramatic reduction in weight.
[0244]
In addition, in a portable terminal intended for personal use such as a portable terminal, a characteristic that only the user himself / herself can recognize information and cannot recognize information from the surroundings is required. The display element of the present invention is very effective for the above-described applications because the light orientation can be strengthened in the front direction.
[0245]
【Example】
Example 1
An opaque substrate made of a composite material of polycarbonate and polyimide is subjected to ultrasonic cleaning for 5 minutes with a detergent (Furuuchi Chemical Co., Semico Clean), ultrasonic cleaning for 10 minutes with pure water, and ammonia water 1 (volume ratio). After 5 minutes of ultrasonic cleaning with a mixed solution of hydrogen peroxide 1 and water 5 and ultrasonic cleaning for 5 minutes with 70 ° C. pure water, water attached to the substrate was removed with a nitrogen blower. Further heating and drying.
[0246]
Next, this substrate is 2 × 10 ^-6 A cathode patterned with a metal mask was formed to a thickness of 150 nm using an Al—Li alloy containing 15 at% Li as a vapor deposition source in a resistance heating vapor deposition apparatus whose pressure was reduced to a vacuum level of Torr or less.
[0247]
Next, in the same manner, in the resistance heating vapor deposition apparatus, Alq as a light emitting layer on the cathode. _Three Was formed with a thickness of about 60 nm, and TPD was formed with a thickness of about 50 nm as a hole transport layer on the light emitting layer. TPD and Alq _Three The vapor deposition rate of was 0.2 nm / s.
[0248]
Next, 2 × 10 ^-6 An ITO film having a film thickness of 160 nm was formed on the hole transport layer by masking with a metal mask in a low damage sputtering apparatus reduced in vacuum to Torr or less.
[0249]
Next, 5 × 10 ^-3 In a vacuum apparatus that has been depressurized to a vacuum level of Torr or less, ultraviolet curable transparent resin is blown out in a mist form from a plurality of nozzles, and a minute hemispherical resin is sprayed onto the surface of the ITO film. Thereafter, ultraviolet rays were irradiated and cured to form a microlens shape on the surface of the ITO film.
[0250]
(Example 2)
An opaque substrate made of silicon is subjected to ultrasonic cleaning for 5 minutes with detergent (Semico Clean, manufactured by Furuuchi Chemical Co., Ltd.), ultrasonic cleaning for 10 minutes with pure water, hydrogen peroxide solution 1 to ammonia water 1 (volume ratio). After washing in the order of ultrasonic cleaning for 5 minutes with a mixed solution of water and water 5 and ultrasonic cleaning for 5 minutes with pure water at 70 ° C., moisture attached to the substrate was removed with a nitrogen blower and dried.
[0251]
Next, this substrate is 2 × 10 ^-6 A cathode patterned with a metal mask was formed to a thickness of 150 nm using an Al—Li alloy containing 15 at% Li as a vapor deposition source in a resistance heating vapor deposition apparatus whose pressure was reduced to a vacuum level of Torr or less.
[0252]
Next, in the same manner, in the resistance heating vapor deposition apparatus, Alq as a light emitting layer on the cathode. _Three Was formed with a thickness of about 60 nm, and TPD was formed with a thickness of about 50 nm as a hole transport layer on the light emitting layer. TPD and Alq _Three The vapor deposition rate of was 0.2 nm / s.
[0253]
Next, 2 × 10 ^-6 An ITO film having a film thickness of 160 nm was formed on the hole transport layer by masking with a metal mask in a low damage sputtering apparatus reduced in vacuum to Torr or less.
[0254]
Next, 2 × 10 ^-6 3 μm of SiO 2 on the ITO film in the sputtering apparatus with a reduced pressure to Torr or lower. ₂ A film was formed.
[0255]
Next, a hemispherical plate is randomly struck on the PET surface to form a reversal mold of a microlens structure, which is formed by a steel mold by transfer by electrodeposition, and by hot working, from a sheet-like polycarbonate A microlens group was formed.
[0256]
Next, an optical adhesive was uniformly applied to the surface of the protective film, and the light angle conversion panel was attached.
[0257]
(Example 3)
A transparent substrate made of glass is subjected to ultrasonic cleaning for 5 minutes with a detergent (Semico Clean, manufactured by Furuuchi Chemical Co., Ltd.), ultrasonic cleaning for 10 minutes with pure water, and aqueous hydrogen peroxide 1 with respect to ammonia water 1 (volume ratio). And 5 minutes of ultrasonic cleaning with a mixed solution of water and water, and then 5 minutes of ultrasonic cleaning with pure water at 70 ° C. Then, water attached to the substrate is removed with a nitrogen blower and further heated. Dried.
[0258]
Next, this substrate is 2 × 10 ^-6 A cathode patterned with a metal mask was formed to a thickness of 150 nm using an Al—Li alloy containing 15 at% Li as a vapor deposition source in a resistance heating vapor deposition apparatus whose pressure was reduced to a vacuum level of Torr or less.
[0259]
Next, in the same manner, in the resistance heating vapor deposition apparatus, Alq as a light emitting layer on the cathode. _Three Was formed with a thickness of about 60 nm, and TPD was formed with a thickness of about 50 nm as a hole transport layer on the light emitting layer. TPD and Alq _Three The vapor deposition rate of was 0.2 nm / s.
[0260]
Next, 2 × 10 ^-6 An ITO film having a film thickness of 160 nm was formed on the hole transport layer by masking with a metal mask in a low damage sputtering apparatus reduced in vacuum to Torr or less.
[0261]
Next, 2 × 10 ^-6 A 3 μm-thick silicon nitride film was formed on the ITO film in a sputtering apparatus whose pressure was reduced to a vacuum level of Torr or less.
[0262]
Next, beads having a diameter of 20 μm made of acrylic were closely arranged, UV-curing transparent resin was poured, and UV irradiation was performed. A transparent film made of acrylic as a flattened surface was adhered to the surface of the hemispherical microlens group formed by this by ultrasonic welding to form a sheet made of the microlens group formed with the flattened surface.
[0263]
Next, an optical adhesive was uniformly applied to the surface of the protective film, and the sheet was attached.
[0264]
(Example 4)
A TFT array in which each pixel electrode made of Cr was connected to a signal line via a TFT made of amorphous silicon was formed on a transparent substrate made of glass.
[0265]
Next, a negative resist material is applied to the surface of the TFT array substrate by a spin coating method to form a resist film having a thickness of 5 μm. A non-light-emitting portion without pixel electrodes is masked, exposed and developed, and only the non-light-emitting portion is Was a TFT array substrate coated with a resist film.
[0266]
Next, this TFT array substrate was cleaned in the order of 5 minutes ultrasonic cleaning with a detergent (Semico Clean, manufactured by Furuuchi Chemical Co., Ltd.) and 10 minutes ultrasonic cleaning with pure water, and then adhered to the substrate with a nitrogen blower. The water was removed and further heated to dry.
[0267]
Next, this TFT substrate is 2 × 10 ^-6 A cathode patterned with a metal mask was formed to a thickness of 150 nm using an Al—Li alloy containing 15 at% Li as a vapor deposition source in a resistance heating vapor deposition apparatus whose pressure was reduced to a vacuum level of Torr or less.
[0268]
Next, in the same manner, in the resistance heating vapor deposition apparatus, Alq as a light emitting layer on the cathode. _Three Was formed with a thickness of about 60 nm, and TPD was formed with a thickness of about 50 nm as a hole transport layer on the light emitting layer. TPD and Alq _Three The vapor deposition rate of was 0.2 nm / s.
[0269]
Next, 2 × 10 ^-6 An ITO film having a film thickness of 160 nm was formed on the hole transport layer in a low damage sputtering apparatus that was depressurized to a vacuum level of Torr or less.
[0270]
Next, a silicon nitride film having a film thickness of 3 μm was formed as a protective film on the uneven organic electroluminescence element in the same manner in a low damage sputtering apparatus.
[0271]
Next, the adhesive sheet formed in the sheet form of thickness 20 micrometers was affixed on the organic electroluminescent element surface protected by this protective film.
[0272]
Next, glass beads having a diameter of about 10 μm on the surface of the pressure-sensitive adhesive sheet were arranged on one side and pressed uniformly on the entire device surface. By repeating the same process three times, beads were uniformly arranged on one surface of the adhesive sheet to form a microlens group.
[0273]
(Comparative Example 1)
An ITO film with a film thickness of 160 nm was formed on a transparent substrate made of glass in the same manner as in Example 1, and then a resist material (manufactured by Tokyo Ohka Co., Ltd., OFPR-800) was applied on the ITO film by a spin coating method. A resist film having a thickness of 10 μm was formed, and the resist film was patterned into a predetermined shape by masking, exposure and development. Next, this substrate is immersed in 50% hydrochloric acid at 60 ° C. to etch the portion of the ITO film where the resist film is not formed. Then, the resist film is also removed, and an anode made of an ITO film having a predetermined pattern A patterning substrate on which was formed was obtained.
[0274]
Next, this patterning substrate is subjected to ultrasonic cleaning for 5 minutes with detergent (Semico Clean, manufactured by Furuuchi Chemical Co., Ltd.), ultrasonic cleaning for 10 minutes with pure water, and aqueous hydrogen peroxide with respect to ammonia water 1 (volume ratio). After cleaning in the order of 5 minutes ultrasonic cleaning with a solution of 1 and water 5 and 5 minutes ultrasonic cleaning with 70 ° C. pure water, water attached to the substrate was removed with a nitrogen blower and further heated. And dried.
[0275]
Next, 2 × 10 2 is applied to the surface of the patterning substrate on the anode side. ^-6 A TPD having a thickness of about 50 nm was formed as a hole transport layer in a resistance heating vapor deposition apparatus that was depressurized to a degree of vacuum of Torr or less.
[0276]
Next, similarly in the resistance heating vapor deposition apparatus, Alq as a light emitting layer on the hole transport layer. _Three Was formed with a film thickness of about 60 nm. TPD and Alq _Three The vapor deposition rate of was 0.2 nm / s.
[0277]
Next, in the same manner, in the resistance heating vapor deposition apparatus, a cathode was formed to a thickness of 150 nm using an Al—Li alloy containing 15 at% Li on the light emitting layer as a vapor deposition source.
[0278]
[Table 1]

[0279]
Here, the evaluation method and the evaluation criteria in the evaluation items of (Table 1) will be described.
[0280]
The luminous efficiency of the device was evaluated by the light emission luminance when a constant current was passed through the organic electroluminescence device. The evaluation criteria are ◎: excellent, ◯: excellent, and Δ: acceptable for the light emission luminance of Comparative Example 1.
[0281]
The visibility of the light emitting surface was evaluated by visually evaluating the degree of visibility with respect to blurring and blurring when the organic electroluminescence element was an image forming apparatus composed of 300 μm pixels. The evaluation is a three-stage evaluation of ◎, 、, and △, and the evaluation criteria are ◎: very good, ◯: excellent, and △: acceptable.
[0282]
The visibility protection of the light emitting surface was evaluated for the ease of removing dust attached to the surface of the organic electroluminescence element. The evaluation criteria are ◎: excellent, ○: excellent, and Δ: acceptable for the ease of removal in Comparative Example 1.
[0283]
As is clear from (Table 1), each of the organic electroluminescent elements of Examples 1, 2, 3, and 4 was superior in emission luminance and light emitting surface visibility to the organic electroluminescent element of Comparative Example 1. As a result. In particular, in Examples 1 and 4, the light emission luminance and the light emitting surface visibility were very excellent compared to Comparative Example 1. However, for the light emitting surface visibility protection, the organic electroluminescence elements of Examples 1, 2, and 4 were inferior to the organic electroluminescence element of Comparative Example 1, but this had no flattened surface. There is no problem in practical use. It turns out that the organic electroluminescent element of a present Example is an organic electroluminescent element which has remarkably high luminous efficiency compared with the comparative example 1, and was excellent in visibility.
[0284]
【The invention's effect】
As described above, according to the organic electroluminescence element of the present invention, the following advantageous effects can be obtained.
[0285]
According to the invention of claim 1,
(1) Since at least two substantially hemispherical micro lens groups having different sizes are formed on the light extraction surface facing the substrate, the area of the light extraction surface / air interface increases, and The probability of total reflection is reduced, and the light extraction efficiency is improved.
[0286]
(2) Since at least two substantially hemispherical micro lens groups having different sizes are formed on the light extraction surface facing the substrate, total reflection at the light extraction surface / air interface is suppressed, and light The take-out efficiency is improved.
[0287]
(3) Since at least two or more substantially hemispherical micro lens groups having different sizes are formed on the light extraction surface facing the substrate, the light distribution changes due to the lens effect. Brightness is improved.
[0288]
(4) Since the minute lens group is formed directly on the light extraction surface, the distance between the lens structure and the light emitting portion can be reduced.
[0289]
(5) Since the minute lens group is formed directly on the light extraction surface, no light loss occurs due to the substrate, and the light extraction efficiency is improved.
[0290]
(6) Since the minute lens group is formed directly on the light extraction surface, the transmission of light in the lateral direction of the pixel surface is suppressed, so that the light extraction is not accompanied by a decrease in visibility such as light bleeding. Efficiency is improved.
[0291]
(7) Since at least two micro lens groups having different sizes are directly formed on the light extraction surface, there is no restriction on the pixel shape and area, and efficient light emission can be maintained over a long period of time. Can do.
[0292]
(8) Since at least two or more micro lens groups having different sizes are directly formed on the light extraction surface, the manufacturing process is simple and can be easily manufactured.
[0293]
According to invention of Claim 2,
(1) Since the microlens group and the flattened surface are formed on the light extraction surface facing the substrate, the area of the microlens group / air interface increases, and the probability of total reflection at the interface decreases. The light extraction efficiency is improved.
[0294]
(2) Since the micro lens group and the flattened surface are formed on the light extraction surface facing the substrate, total reflection at the micro lens group / air interface is suppressed, and the light extraction efficiency is improved.
[0295]
(3) Since the minute lens group is formed directly on the light extraction surface, the distance between the lens structure and the light emitting portion can be reduced.
[0296]
(4) Since the surface of the light extraction surface of the microlens group is formed with an air layer and a flattened surface that becomes flat via some contacts, dust or the like is formed on the surface of the light extraction surface. Even if it adheres, the value of the light extraction efficiency does not decrease.
[0297]
(5) Since the flattened surface is formed on the light extraction surface side, even if dust or the like adheres to the surface of the light extraction surface, it can be easily removed.
[0298]
(6) Since the flattened surface is formed on the light extraction surface side, the microlens group is not in direct contact with the outside air, so that the lens effect can be maintained for a long time.
[0299]
(7) Since the flattened surface is formed on the light extraction surface side, a sheet or the like for preventing a decrease in visibility due to external light can be easily formed on the surface of the light extraction surface.
[0300]
(8) Since the flattened surface is formed on the light extraction surface side, it is possible to suppress the change in the shape of the micro lens group even when a force is applied from the outside.
[0301]
(9) Since the microlens group is formed with a flattened surface on the light extraction surface side, the influence on the light extraction efficiency is small even if the flattened surface is thickened, so that the strength of the microlens group can be easily maintained. It is.
[0302]
According to invention of Claim 3, in addition to the effect of Claim 1 or 2,
(1) Since the minute lens group is pasted on the light extraction surface via an optical coupling material, the light emitting portion and the minute lens group can be individually manufactured, and light emission generated when the minute lens group is formed. The influence of the factors that cause damage to the layer can be eliminated, and the microlens group and the light emitting portion can be easily manufactured.
[0303]
(2) Since the minute lens group is pasted on the light extraction surface via an optical coupling material, the light emitting portion and the minute lens group can be individually manufactured, and the minute lens group is formed as one sheet. Is possible and easy to handle.
[0304]
(3) Since the light emitting portion and the micro lens group can be individually manufactured, the micro lens group formed by forming a flattened surface on the light extraction surface side can be formed as one sheet. Since both surfaces are flat, handling is easy.
[0305]
(4) Since the minute lens group is pasted on the light extraction surface via an optical coupling material, it can be easily pasted even if the surface shapes of the minute lens group and the light emitting portion do not match.
[0306]
(5) Since the minute lens group including the minute lens group and the flattened surface can be formed as one sheet, the sheet can be integrated with the sheet for preventing the visibility from being deteriorated by external light. Can be formed.
[0307]
According to the invention of claim 4, in addition to the effect of any one of claims 1 to 3,
(1) Since the refractive index of the minute lens group is large, light that cannot reach the minute lens group due to total reflection can be reduced, and light extraction efficiency is improved.
[0308]
(2) Since the refractive index of the minute lens group is large, the light reaching the minute lens group is increased, the lens effect of the minute lens group can be made effective, and the light extraction efficiency is improved.
[0309]
(3) Since the refractive index of the micro lens group is large, the light emitted from the light emitting layer is oriented in the normal direction of the light emitting surface, and the light loss inside the device can be reduced, and the visibility is excellent. In addition, highly efficient light emission performance can be maintained.
[0310]
According to invention of Claim 5, in addition to the effect of any one of Claims 1 to 4,
(1) Since light loss inside the device can be reduced, high-efficiency light-emitting performance with excellent visibility can be maintained.
[0311]
(2) Light loss inside the device is reduced, and light that is not extracted into the air due to total reflection is reflected by the reflective electrode and can be reused, maintaining excellent light emission performance with excellent visibility. can do.
[0312]
According to the invention described in claim 6, in addition to the effect of any one of claims 1 to 5,
(1) Since the functions can be shared like a member that can be easily processed and a member that can maintain strength, the choice of materials increases.
[0313]
(2) By using a plurality of materials, it is possible to give the minute lens group a complicated function.
[0314]
(3) Arbitrary visibility can be given by appropriately selecting a material to be used.
[0315]
According to the invention described in claim 7, in addition to the effect of any one of claims 1 to 6,
(1) Since the light emitting layer is protected by the protective film, the number of manufacturing process options for forming the microlens group is increased, and the microlens group can be easily formed.
[0316]
(2) Since the light emitting layer is protected by the protective film, the choice of materials for forming the microlens group is increased, and the microlens group can be easily formed.
[0317]
(3) Since the light emitting layer is protected by the protective film, the options of the optical coupling material for attaching the microlens group are increased, and the microlens group can be easily attached.
[0318]
(4) Since the light emitting layer is protected by the protective film, the choice of the application method of the optical coupling material which affixes a microlens group increases, and a microlens group can be easily affixed.
[0319]
According to the invention described in claim 8, in addition to the effect of claim 7,
(1) Light that cannot reach the micro lens group due to total reflection can be reduced, and light extraction efficiency is improved.
[0320]
(2) Since the light reaching the minute lens group increases, the effect of the minute lens group can be made effective, and the light extraction efficiency is improved.
[0321]
(3) Since the light emitted from the light emitting layer is oriented in the normal direction of the light emitting surface, the light loss inside the device can be reduced, and the light emitting performance with excellent visibility and high efficiency is achieved. Can be maintained.
[0322]
According to invention of Claim 9, in addition to the effect of Claim 7 or 8,
(1) Since light loss inside the device can be reduced, high-efficiency light-emitting performance with excellent visibility can be maintained.
[0323]
(2) Light loss inside the device is reduced, and light that is not extracted into the air due to total reflection is reflected by the reflective electrode and can be reused, maintaining excellent light emission performance with excellent visibility. can do.
[0324]
According to the invention of claim 10, in addition to the effect of any one of claims 3 to 9,
(1) Light that cannot reach the micro lens group due to total reflection can be reduced, and light extraction efficiency is improved.
[0325]
(2) Since the light reaching the minute lens group increases, the effect of the minute lens group can be made effective, and the light extraction efficiency is improved.
[0326]
(3) Since the light emitted from the light emitting layer is oriented in the normal direction of the light emitting surface, the light loss inside the device can be reduced, and the light emitting performance with excellent visibility and high efficiency is achieved. Can be maintained.
[0327]
According to the invention of claim 11, in addition to the effect of any one of claims 3 to 10,
(1) Since light loss inside the device can be reduced, high-efficiency light-emitting performance with excellent visibility can be maintained.
[0328]
(2) Light loss inside the device is reduced, and light that is not extracted into the air due to total reflection is reflected by the reflective electrode and can be reused, maintaining excellent light emission performance with excellent visibility. can do.
[0329]
According to the invention of claim 12, in addition to the effect of any one of claims 3 to 11,
(1) Since the optical coupling material has an appropriate flexibility at the time of attaching the microlens group and the light emitting layer, it can be easily attached even if the surface portions of the microlens group and the light emitting layer are different.
[0330]
(2) The optical binder can be easily applied because the optical binder has appropriate flexibility when the microlens group and the light emitting layer are attached.
[0331]
(3) Since there is flexibility between the microlens group and the light emitting layer, it is strong against stress such as bending and can maintain a highly efficient light emitting performance with excellent visibility over a long period of time.
[0332]
(4) Since there is flexibility between the micro lens group and the light emitting layer, it is easy to form a flexible element that is strong against stress such as bending.
[0333]
According to the invention of claim 13, in addition to the effect of any one of claims 3 to 12,
(1) By appropriately selecting heat or light necessary for curing the optical binder, the microlens group and the light emitting layer can be easily attached without damaging the light emitting layer.
[0334]
(2) Since the positional relationship between the microlens group and the light emitting layer is maintained after the optical binder is cured, it is possible to maintain highly efficient light emitting performance with excellent visibility over a long period of time.
[0335]
(3) By appropriately selecting the thickness and material of the optical binder, it is possible to maintain high-efficiency light-emitting performance that is strong against stress such as bending and excellent in visibility over a long period of time.
[0336]
(4) By appropriately selecting the thickness and material of the optical coupling material, it is easy to form a flexible element that is strong against stress such as bending.
[0337]
According to the invention of claim 14, in addition to the effect of any one of claims 1 to 13,
(1) Since light loss inside the device can be reduced, high-efficiency light-emitting performance can be maintained over a long period of time, and good illumination can be performed using a simple matrix method.
[0338]
(2) Since the anode and the cathode are electrically separated in stripes, a large light emitting portion in the pixel can be obtained.
[0339]
(3) In the case of a simple matrix, instantaneous high brightness is required, so this high efficiency and a large area of the light emitting part are very important.
[0340]
According to the fifteenth aspect of the present invention, in addition to the effect of any one of the first to thirteenth aspects, this configuration provides the following operation.
[0341]
(1) Since light loss inside the device can be reduced, high-efficiency light-emitting performance can be maintained over a long period of time, and good illumination with an active matrix system can be performed.
[0342]
(2) Since the anode or cathode is configured to be electrically separated for each pixel, instantaneous high brightness is not necessary, it is sufficient for practical use, and stable light emission is maintained over a long period of time. can do.
[0343]
(3) Since the anode or the cathode is scanned through at least one or more switching elements, free image formation can be realized, and the high-speed response characteristic of the organic electroluminescence element can be fully utilized.
[0344]
(4) In the case of an active matrix, the light emitting part is often formed on an uneven surface by a switching element, wiring or the like arranged in a pixel. Therefore, a measure for obtaining highly efficient light emission even on such an uneven surface is very advantageous.
[0345]
According to the invention of claim 16, in addition to the effect of claim 14 or 15,
(1) By setting the diameter of the minute lens forming the minute lens group to be smaller than the long side of the pixel, at least one minute lens can be arranged in one pixel. The same effect of improving the extraction efficiency can be obtained, and a good image can be obtained.
[0346]
(2) Since the distance from the light emitting portion to the top portion of the microlens can be reduced, it is possible to maintain highly efficient light emitting performance with excellent visibility.
[0347]
According to the invention of claim 17, in addition to the effect of any one of claims 14 to 16,
(1) By setting the diameter of the minute lens forming the minute lens group to be smaller than the short side of the pixel, at least one minute lens can be densely arranged in the pixel. The same effect of improving the extraction efficiency can be obtained, and a good image can be obtained.
[0348]
(2) At least one or more microlenses can be densely arranged in a pixel, and uniform light with no directivity can be taken out in any pixel to obtain a good image with excellent visibility. be able to.
[0349]
(3) Since the distance from the light emitting portion to the top portion of the microlens can be made extremely small, it is possible to maintain highly efficient light emitting performance with excellent visibility.
[0350]
According to invention of Claim 18, in addition to the effect of any one of Claims 14 to 17,
(1) Since the distance from the light emitting portion to the outermost surface of the micro lens group is smaller than the long side of the pixel, the light bleed spreads as long as the long side of the pixel, maintaining high visibility and high efficiency light emitting performance. be able to.
[0351]
(2) Since the distance from the light emitting portion to the outermost surface of the micro lens group is smaller than the long side of the pixel, the spread of the light in the horizontal direction is about the long side of the pixel, and the light can be easily reused. In addition, it is possible to maintain a high-efficiency light-emitting performance.
[0352]
According to the invention of claim 19, in addition to the effect of any one of claims 14 to 18,
(1) Since the distance from the light emitting part to the outermost surface of the micro lens group is smaller than the short side of the pixel, the light blur spreads about the short side of the pixel, and the light emission performance is high definition and excellent in visibility. Can be maintained.
[0353]
(2) Since the distance from the light emitting portion to the outermost surface of the micro lens group is smaller than the short side of the pixel, the lateral spread of the light is about the short side of the pixel, the light reuse efficiency is high, and visibility is improved. Excellent and highly efficient luminous performance can be maintained.
[0354]
According to the invention of claim 20, in addition to the effect of any one of claims 14 to 19,
(1) Light loss inside the device can be reduced, so that high-efficiency light-emitting performance can be maintained, and weight reduction or longer use time can be achieved by reducing battery capacity and the like. it can.
[0355]
(2) By appropriately designing the visual characteristics (light orientation), it can be used as a private window that is difficult to see from the surroundings, a window that can be easily viewed by a plurality of people, and the like depending on the application.
[0356]
(3) By using a display means having a flattened surface on the light extraction surface, the microlens is not directly exposed to the surface, so even if dust or other dust is attached, it is highly efficient with excellent visibility. An image display can be obtained.
[0357]
(4) Since an antifouling film or the like can be easily pasted on the flattened surface on the light extraction surface, dust such as dust can be easily removed.
[0358]
According to the invention of claim 21,
(1) An organic electroluminescence device capable of maintaining light emission performance over a long period of time can be produced with a simple process.
[0359]
(2) Since the forming method is simple, workability is high and productivity is high.
[0360]
(3) Since it can be formed in a consistent vacuum, it is possible to produce an organic electroluminescence device that has high workability, high productivity, and is stable over a long period of time.
[0361]
According to the invention of claim 22,
(1) An organic electroluminescence device capable of maintaining light emission performance over a long period of time can be produced with a simple process.
[0362]
(2) Since the forming method is simple, workability is high and productivity is high.
[0363]
(3) A dense micro lens group can be easily formed, and a highly efficient organic electroluminescence element can be produced.
[0364]
According to the invention of claim 23,
(1) Organic electroluminescence capable of maintaining light emission performance over a long period of time can be created with a simple process.
[0365]
(2) Since the forming method is simple, workability is high and productivity is high.
The effect is obtained.
[0366]
According to the invention of claim 24,
(1) Organic electroluminescence capable of maintaining light emission performance over a long period of time can be created with a simple process.
[0367]
(2) Since the forming method is simple, workability is high and productivity is high.
[0368]
According to the invention of claim 25, the area of the light extraction surface / air interface is increased, the probability of total reflection at the interface is decreased, and the light extraction efficiency is improved.
[0369]
And, the provision of an organic electroluminescence element capable of maintaining high-efficiency light-emitting performance with excellent visibility, the provision of an image forming apparatus capable of maintaining high-efficiency light-emitting performance with excellent visibility, and weight It is possible to provide a method of manufacturing an organic electroluminescence element that is light and has a long use time, can be formed by a simple process, has high workability, and high productivity.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an organic electroluminescence element in an embodiment of the present invention.
FIG. 2 is a graph showing the result of optical simulation.
FIG. 3 is a cross-sectional view of a main part of the organic electroluminescence element in the first embodiment.
4 is a cross-sectional view of main parts of an organic electroluminescence element according to Embodiment 2. FIG.
5 is a schematic perspective view of an image forming apparatus using an organic electroluminescence element according to Embodiment 3. FIG.
6 is a perspective view showing a portable terminal using the organic electroluminescence element of Embodiment 4. FIG.
FIG. 7 is a block diagram showing a portable terminal using the organic electroluminescence element of the present invention.
FIG. 8 is a cross-sectional view of a main part of a conventional organic electroluminescence element.
FIG. 9 is a schematic diagram showing a typical light beam path in a cross section of a main part of a conventional organic electroluminescence element.
[Explanation of symbols]
1 Substrate
2 Anode
3 Hole transport layer
4 Light emitting layer
5 Cathode
6 Micro lens group
7 Optical coupling material
8 Protective film
9 Light source of light emitted from the light emitting layer
10 Microphone
11 Speaker
12 Operation unit
13 Display section
14 Antenna
15 Transmitter
16 Receiver
17 Control unit

Claims (15)

An anode for injecting holes on the substrate;
A cathode for injecting electrons;
A light emitting portion that emits light by recombination of holes injected by the anode and electrons injected by the cathode, between the anode and the cathode;
A lens portion formed of a substantially hemispherical microlenses provided on the opposite side of the light-emitting portion with respect to the cathode,
An organic electroluminescence element having a planarized surface provided through an air layer and a part of contacts on a side of the lens portion on which a substantially spherical surface of a minute lens is formed. An anode for injecting holes on the substrate;
A cathode for injecting electrons;
A light emitting portion that emits light by recombination of holes injected by the anode and electrons injected by the cathode, between the anode and the cathode;
A lens part provided on the opposite side of the light emitting part with respect to the cathode and formed with a plurality of microlenses having various substantially hemispherical sizes,
An organic electroluminescence element having a planarized surface provided through an air layer and a part of contacts on a side of the lens portion on which a substantially spherical surface of a minute lens is formed. The organic electroluminescence element according to claim 1, wherein the lens unit is attached to a light extraction surface via an optical coupling material. The organic electroluminescent element according to any one of claims 1 to 3, wherein the lens portion is made of a material having a refractive index higher than a refractive index of 1.4. 5. The organic electro luminescent device according to claim 1, wherein the lens portion is formed of a transparent material capable of emitting 50% or more of light emitted from the light emitting layer. Luminescence element. 5. The organic electroluminescence element according to claim 1, wherein the lens unit is formed by optically coupling at least two materials. 6. The organic electroluminescent element according to claim 1, wherein the lens portion is formed on a protective film formed on a surface of the organic electroluminescent element. The organic electroluminescence device according to claim 7, wherein the protective film is made of a material having a refractive index higher than a refractive index of 1.4. 9. The organic electroluminescence device according to claim 7, wherein the protective film is made of a transparent material capable of emitting 50% or more of light emitted from the light emitting layer. The organic electroluminescent element according to claim 3, wherein the optical coupling material is made of a material having a refractive index higher than a refractive index of 1.4. The said optical coupling material is formed with the transparent material which can discharge | release 50% or more of the light radiated | emitted from the said light emission part, The any one of Claims 3 thru | or 10 characterized by the above-mentioned. Organic electroluminescence device. The organic electroluminescent element according to claim 3, wherein the optical coupling material is made of a liquid or gel material. The organic electroluminescent element according to claim 3, wherein the optical binder is made of a material that is cured by heat or light. 14. The organic electroluminescence device according to claim 1, wherein the anode and the cathode are individually electrically separated in a stripe shape and have an image display array including a plurality of pixels. A featured image forming apparatus. 14. The organic electroluminescence device according to claim 1, wherein the anode or the cathode is configured to be electrically separated for each pixel, and the separated electrode includes at least one or more electrodes. An image forming apparatus having an image display arrangement by being scanned through a switching element.

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